28621509 has 8 divisors (see below), whose sum is σ = 43613760. Its totient is φ = 16355136.

The previous prime is 28621507. The next prime is 28621511. The reversal of 28621509 is 90512682.

It is an interprime number because it is at equal distance from previous prime (28621507) and next prime (28621511).

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 28621509 - 2¹ = 28621507 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 28621509.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28621507) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 681444 + ... + 681485.

It is an arithmetic number, because the mean of its divisors is an integer number (5451720).

Almost surely, 2^28621509 is an apocalyptic number.

It is an amenable number.

28621509 is a deficient number, since it is larger than the sum of its proper divisors (14992251).

28621509 is a wasteful number, since it uses less digits than its factorization.

28621509 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1362939.

The product of its (nonzero) digits is 8640, while the sum is 33.

The square root of 28621509 is about 5349.9073823759. The cubic root of 28621509 is about 305.8892225782.

It can be divided in two parts, 2862 and 1509, that added together give a triangular number (4371 = T₉₃).

The spelling of 28621509 in words is "twenty-eight million, six hundred twenty-one thousand, five hundred nine".